In fact I claim the opposite; Snowden cannot control the media, and should have predicted its inevitable reaction to the input he has been feeding it.
Ah, and were he not to have done so, are we so sure the NSA bits and pieces would be dominating the headlines, or might those have drifted into the background regardless? Wovon man nicht sprechen kann, darueber muss man schweigen.
Last time I checked Greenwald is not an idiot. The ongoing leaks have come without any interaction by Snowden at all, if I'm understanding him correctly. If anything he keeps stealing the thunder of WaPo, Guardian, Der Spiegel, etc.
Media is controlling him, not like mathematical control of direct or inverse relations but more of a sublte control.